Carrier tracking loop based on self-adaptive second-order Kalman filter and filtering method of carrier tracking loop

Abstract

The invention discloses a carrier tracking loop based on a self-adaptive second-order Kalman filter and a filtering method of the carrier tracking loop. The carrier tracking loop based on the self-adaptive second-order Kalman filter comprises a local carrier generator, an integral clearer, a carrier loop phase discriminator, a loop filter and the self-adaptive second-order Kalman filter. The invention overcomes the defect of tracking loop lock losing caused by divergence of the traditional Kalman filter when priori information is inaccurate. When a system model is incomplete or the priori information is inaccurate, a forecast error covariance matrix is self-adaptively regulated through fading factors, thus the purpose of regulating a gain matrix in real time is achieved, the filter approaches the optimal, and the divergence of the filter can be effectively inhibited. Meanwhile, the carrier tracking method has the advantages of simpleness in calculation of a method of estimating the fading factors, small calculated amount, strong adaptability and reliability improvement of a filtering algorithm.

Description

technical field [0001] The invention belongs to the technical field of GPS baseband signal processing, and in particular relates to a carrier tracking loop based on an adaptive second-order Kalman filter and a filtering method thereof. Background technique [0002] In recent years, with the rapid development of aviation and aerospace technology and its wide application in military affairs, the application of GPS system in high dynamic environment has been paid more and more attention by people. So far, foreign countries have continuously put high-dynamic GPS related products into actual war applications. For example, Tomahawk cruise missiles and Slam missiles are all guided by high-dynamic GPS receivers. Their superior reliability and high precision have enabled the United States to obtain a huge military effect in the Gulf War and the Kosovo War. At present, the high-dynamic application field of GPS system is still expanding. Most of the military aircraft in the United Sta...

AI Technical Summary

Problems solved by technology

[0005] The present invention aims at the problems existing in the GPS carrier tracking loop in the high dynamic environment existing in the prior art, and proposes a carrier tracking loop based on an adaptive second-order Kalman filter and its filtering method

The invention overcomes the disadvantage that the traditional Kalman filter causes the filter to diverge when the prior information is inaccurate, thus causing the tracking loop to lose lock

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